<template>
  <el-container class="home-container">
    <!-- 头部区域 -->
    <el-header>
      <div>
        <img src="../assets/logo.png">
        <span>电商后台管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <!-- 页面主体 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px' ">
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <el-menu 
        background-color="#333744" 
        text-color="#fff" 
        active-text-color="#409eff" 
        unique-opened 
        :collapse="isCollapse" 
        :collapse-transition="false"
        router
        :default-active="activePath">
          <!-- 一级菜单 -->
          <el-submenu :index="item.id + ''" :key="item.id" v-for="item in menulist">
            <!-- 一级菜单模板 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span>{{item.authName}}</span>
            </template>

            <!-- 二级菜单 通过 index 帮助router跳转地址  -->
            <el-menu-item 
            :index="'/'+subItem.path" 
            :key="subItem.id" 
            v-for="subItem in item.children"
            @click="savesNavState('/'+subItem.path)">
              <!-- 模板 -->
              <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-menu"></i>
                <!-- 文本 -->
                <span>{{subItem.authName}}</span>
              </template>               
            </el-menu-item>

          </el-submenu>

        </el-menu>

      </el-aside>
      <!-- 页面内容 -->
      <el-main>
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      // 左侧菜单数据
      menulist:[],
      iconsObj:{
        '125': 'iconfont icon-user',
        '103': 'iconfont icon-zhongchuangkongjian-',
        '101': 'iconfont icon-shopping-bag',
        '102': 'iconfont icon-danju-tianchong',
        '145': 'iconfont icon-baobiao'
      },
      // 是否折叠，不折叠
      isCollapse:false,
      // 点击导航链接的激活状态
      activePath:''
    }
  },
  created () {
    this.getMenuList();
    this.activePath = window.sessionStorage.getItem('activePath');
  },
  methods: {
    logout() {
      window.sessionStorage.clear();
      this.$router.push('/login');
    },
    // 获取菜单列表
    async getMenuList () {
      const { data: res } = await this.$http.get('menus');
      if(res.meta.status !== 200) return this.$message.error('res.meta.msg');
      this.menulist = res.data;
    },
    // 点击按钮，切换菜单的折叠与展开
    toggleCollapse () {
      this.isCollapse = !this.isCollapse;
    },
    // 保存链接的激活状态
    savesNavState (activePath) {
      window.sessionStorage.setItem('activePath', activePath);
      this.activePath = activePath;
    }
  }
}
</script>

<style lang="less" scoped>
.home-container{
  height: 100%;
}
.el-header{
  background:#373d41;
  display: flex;
  justify-content: space-between;
  padding-left: 0;
  align-items: center;
  color: #fff;
  font-size: 20px;
  > div{
    display: flex;
    align-items: center;
    span{
      margin: 0 5px;
    }
    img{
      height: 46px;
    }
  }
}
.el-aside{
  background:#333744;
  .el-menu{
    border-right: 0;
  }
}
.el-main{
  background:#eaedf1;
}
.iconfont{
  margin-right: 10px;
}
.toggle-button{
  background:#4a5064;
  font-size: 10px;
  line-height: 28px;
  text-align: center;
  color: #fff;
  letter-spacing: 0.2em;
  cursor: pointer;
}
</style>